I don't understand why two currencies are put together as one [opgelost]

Hi! I was a little confused when I came accross the currency listed for this coin:

https://en.numista.com/catalogue/pieces2446.html

It reads: Nuevo sol (1991-2015) / Sol (2016-date)

Is it just me or does that list two different currencies together??

I'm not that good with Peru currencies so if someone could help me understand this that would be great. Thanks!

It's the same currency just at one point they dropped the "new" ... but I think this is not the best solution.
Maybe drop the Nuevo altogether in the currency?

Citeer: "Idolenz"​It's the same currency just at one point they dropped the "new" ... but I think this is not the best solution.
​Maybe drop the Nuevo altogether in the currency?

​Hmmm.. I read a little more about the history in dropping the Nuevo at this site:

https://www.howtoperu.com/in-with-the-sol-out-with-the-new/

I understand why two "different" currencies are listed on the same line now. If you have a counter-argument I would be glad to hear it as I am not the best at currency history. Thanks for the help!